The 2017–18 FC Basel season was the 125th season in club history and the club's 23rd consecutive season in the top flight of Swiss football. Basel were the reigning Swiss Super League champions. The season started on the weekend of 22–23 July 2017 and ended on 19 May 2018. They were also the Swiss Cup holders. The first round of the Swiss Cup was played on 13 August 2017. Basel were also qualified for this season's Champions League in the Group stage. The first round was played on 12 September 2017.